Mesoporous core–shell structured nanocatalysts with a PdPt bimetallic core and enzyme-immobilized polydopamine (PDA) shell were designed, in which the PDA shell worked as a barrier to position the bimetallic core and enzyme in separated locations. The accessible mesoporous structures of both the core and shell significantly facilitate mass transfer and catalyst utilization, improving the synergistic catalytic abilities in cascade reactions. The obtained bifunctional nanocatalysts enabled efficient two-step one-pot cascade reactions of different types: dynamic kinetic resolution of primary amines in organic solvent with high yield and enantioselectivity (up to 99% yield and 98% ee) and degradation of organophosphate nerve agent in aqueous solution with high rate constant and turnover frequency number values (0.8 min–1 and 20 min–1, respectively).